Why do you need a model sheet ?

I aim to be a 1:1 3D Modeler

I aim to be a 1:1 3D Modeler, meaning that I'll try my best to stick to the reference as closely as I can. Essentially, no model sheet means no model, since I don’t have a reference.

Time and Sanity consuming

Modeling for someone else is already time and sanity consuming. But modeling without a model sheet is very time and sanity consuming. A model sheet means that you are already satisfied with the design, and that you are less likely to change things on it. It’s often quicker to alter a design in 2D than it is in 3D. I am not willing to spend 1/3 of the total working hours changing stuff because we don't have the same vision.

Can’t you make a model sheet on your own if I give you multiple references?

I am a 3D Artist, not a 2D Artist

As of now, I offer 3D services, not 2D. I am not a 2D Artist that offers Charadesign / Character Model Sheets services. You may occasionally see me post original character model sheets on my socials. I drew them myself. So why can’t I do the same for you? When I draw, I mostly draw for myself. I know what I want and what works in 3D. There’s a huge gap between that, and trying to guess what someone else wants, even when provided with multiple references. That’s a separate set of skills. Unless you give me total freedom on your character design, style and quality, I cannot make the model sheet on my own.